Three printed pages, entitled "Testimony of Chris Walker," are a precious keepsake for the parents of the young man shot to death at an Altadena hamburger stand.
"I now have goals and dreams that I never before imagined," Walker wrote at age 20, when he resolved to leave gang life.
"I'm proud of the person he was becoming -- he became. Because I know for a fact he had really changed his life," said mother Ursula Walker. "And I'm so sorry that someone took it."
On October 30, 2014, six years after he dictated his testimony, after he had launched a career in marketing, as he was putting his life in order, Chris Walker was shot to death at an Altadena hamburger stand. It was 4:30 in the afternoon, broad daylight.
After ordering at the counter, Walker was sitting outside, waiting for his food, when a gunmen approached from a side street, fired the fatal shots, then departed in a car described as a light-colored sedan, said Det. Sgt. Chaffey Shepherd of the Los Angeles County Sheriff's Homicide Bureau.
Nineteen months later, with leads exhausted, detectives convinced Los Angeles County Supervisors to post a reward of $20,000, in the hope it will bring forward witnesses.
Members of the Walker Family joined detectives at the Sheriff's Hall of Justice Wednesday with an appeal for the public's help.
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"I just hope somebody will come forward, because I know there are people who saw what happened," said Christopher's sister Nicole Walker, 25, as she fought back tears.
It's believed that after the shooting at Fair Oaks Burger, several individuals scattered without ever contacting law enforcement to report what they witnessed.
The shooter did not rob his victim. There are indications it was a gang shooting, Det. Sgt. Shepherd said, though why Walker was targeted is unclear.
It is a case that hits close to home for NBC4: His father, Richard Walker, works as an engineer in NBC4's news operations center.
Walker and his wife believe their son was indoctrinated into gang life as young as age 5 when he played T-ball at a park where some of the young coaches turned out to be gang members, Richard said.
Behavioral issues became more severe as Christopher grew older.
His parents tried counseling and intervention programs, but eventually Christopher left home.
"He really had to move out. We couldn't handle him anymore," Richard said.
After high school, Walker went to Arizona in live, getting a job and a new outlook on life, his parents said. It was during that time that Richard visited his son and they reconciled.
"After a few years he felt like, 'I can come back now, I'm OK. I'm not in that life anymore,'" his father said wistfully. "But I guess some people never let go."
It was a reference to the family's suspicion that Christopher's long ago gang association was not forgotten in Altadena, and may have led to the unprovoked attack that claimed his life.
After returning to Southern California from Arizona in 2013, Christopher Walker lived several months with his parents, then got his own place, ultimately renting a small house in Duarte. The marketing firm where he worked was located in downtown Los Angeles, only three blocks from his mother's office. Every morning, he would drive to his parents' home in Pasadena, and then he and his mother would carpool to downtown.
When Christopher arrived each day around 6 a.m., he would take off his shoes and tiptoe into the house so as not to awaken his father, still asleep because he worked late, his mother recalled.
Both parents treasure their final memories of Christopher on what proved to be his last day. He finished work early, and went to his mother's office to get his keys from her car.
"He gave me a big hug and a kiss," Ursula recalled. "He said, 'I love you, Momma."
Shortly thereafter, when Christopher arrived at the family home to get his car, he went inside to change clothes and visit with his dad. He forgot and left his second pair of shoes, but Richard Walker was not worried -- Christopher could pick them up when he returned in the morning.
Then came a knock on the door with word of what had happened at the burger stand.